Reflect in naming that negative SelfHealing is a thing.

OpenRA.Mods.Common/UpdateRules/Rules/RenameSelfHealing.cs

@@ -0,0 +1,42 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Collections.Generic;
+using System.Linq;
+
+namespace OpenRA.Mods.Common.UpdateRules.Rules
+{
+	public class RenameSelfHealing : UpdateRule
+	{
+		public override string Name { get { return "SelfHealing was renamed as negative SelfHealing is a common usecase."; } }
+		public override string Description
+		{
+			get
+			{
+				return "SelfHealing was renamed to ChangesHealth\n" +
+						"HealIfBelow was renamed to StartIfBelow.";
+			}
+		}
+
+		public override IEnumerable<string> UpdateActorNode(ModData modData, MiniYamlNode actorNode)
+		{
+			var modId = modData.Manifest.Id;
+
+			foreach (var sh in actorNode.ChildrenMatching("SelfHealing"))
+			{
+				sh.RenameChildrenMatching("HealIfBelow", "StartIfBelow");
+				sh.RenameKey("ChangesHealth");
+			}
+
+			yield break;
+		}
+	}
+}